In the 3rd Generation Partnership Project (3GPP), a radio access method and a radio network for cellular mobile communications (hereinafter, referred to as “Long Term Evolution (LTE)”, or “Evolved Universal Terrestrial Radio Access (EUTRA)”) have been studied (NPL 1). In LTE, a base station device is also referred to as an evolved NodeB (eNodeB), and a terminal device is also referred to as User Equipment (UE). LTE is a cellular communication system in which multiple areas each covered by the base station device are deployed to form a cellular structure. In such a cellular communication system, a single base station device may manage multiple cells.
LTE supports a Time Division Duplex (TDD). LTE that employs the TDD scheme is also referred to as TD-LTE or LTE TDD. In TDD, uplink signals and downlink signals are time division multiplexed. Furthermore, LTE supports a Frequency Division Duplex (FDD).
In 3GPP, latency reduction enhancements have been studied. For example, for the latency reduction enhancements, Scheduling request first grant or Pre-scheduled first grant has been studied (NPL 2).